1. Field of the Invention
The present invention is related to a brand new antenna structure, and especially to an antenna structure having a serial connected capacitance effect.
2. Description of the Prior Art
By fast development of communication techniques, mobile equipment are required to be compacted in volume, multi-frequency metallic planar antennas have become mainstream elements of mobile phones or notebooks for receiving or emitting radio signals.
Traditionally, metallic planar antennas are connected with circuit boards in mobile equipment via SMT elements. By virtue that normal SMT elements are designed to be impedances of fixed standard values, antennas still need matched electric circuits to adjust the values of capacitances and inductances, this may induce inconvenience of designing, and limit the frequency widths and effects of the antennas. Therefore, improvement is expected.
In a U.S. Pat. No. 6,542,123 titled “HIDDEN WIDEBAND ANTENNA” of the applicant, an inwardly recessed section, a back folded section and a protruding sheet extend out of an antenna for adjusting matching frequency. By the fact that the measures used in the patent makes elongation of the antenna to be unable to appropriately adjust values of capacitances and inductances, the designing of antennas still is limited.